Resilient driving connection.



J. E. WEBSTER.

RESILIENT DRIVING CONNECTION.

APPLICATION FILED JULY 24, 1911.

1 ,089, 1 68, Patented Mar. 3, 1914.

2 SHBETS-SHEET 1.

0 Deflecfum WITNESSES: (g INVENTOR BY I AiTORN EY J. B. WEBSTER.

BESILIBNT DRIVING CONNECTION. w APPLICATION FILED JULY 24, 1911.

1,089,168, Patented Mar. 3, 1914.

2 SHEETS-SHEET 2.

WITNESSES: 3 g NVENTOR 9 WM ATTORNEY UNITED STATES PATENT OFFICE.

JOHN E. WEBSTER, OF PITTSBURGH, PENNSYLVANIA, ASSIGNOR TO WESTINGHOUSE ELECTRIC AND MANUFACTURING COMPANY, A CORPORATION OF PENNSYLVANIA.

RESILIENT DRIVING CONNECTION.

Patented Mar. 3, 1914.

Application filed July 24, 1911. Serial No. 640,194.

To all whom it may concern:

Be it known that I, JOHN E. WEBSTER, a citizen of the United States, and a resident of Pittsburgh, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvement in Resilient Driving Connections, of which the follow.- ing is a specification.

My invention relates to yielding connections and particularly to such resilient driving connections as are interposed between the propelling motors and the driving wheels of electric vehicles. M

In Reissue Patent No. 13,165, granted November 8, 1910, to the WVestinghouse Electric & Manufacturing Company, on a reissue application filed by me June 25, 1910, I have shown and described a resilient connection adapted for the purposes outlined above and comprising, general, helical springs interposed between two relatively movable members and provided with means for circumferentially gripping convolutions of the springs and clamping the sameto the respective members. 1

ie object of my present invention is to provide a simple and durablespring whieh,in proportion to its length, is capable of resisting very'much larger working forces tending to extend or compress it, without materially increasing the lateral forces necessary to deflect it, and a driving connection embodying the same. I

In order to accomplish the aforesaid objective results, I provide a;plurality of-driving springs, each consisting of several closed turns (2'. 0., turns having their pitch distance equal to the diameter of the spring wire) at its respective ends, which are adapted to be clamped to the movable members with which it is used, and a plurality of intermediate open turns of symmetrically varying diameters, the turns of shortest mean length being located near the middle of the spring.

Figure 1 of the accompanying drawings is a partially sectional end elevation illustrating a portion of a wheel and driving mechanism, constructed in accordance with my invention. Fig. 2 is a diagram illustrating by means of curves, the characteristics of the spring shown in Fig. 1 of the drawings, as compared to a spring of the same general pro-portions of the ordinary type. Figs. 3 and 1 are detail views of the spring clamp of Fig. 1 and Fig. 5 is a sectional view on the line V-V of Fig. 1, showing a portion of an electric motor by which the wheel is propelled.

Referring to Figs. 1, 3, 4 and 5, of the drawings, an electric motor 1 comprises a relatively stationary field magnet frame 2, an armature 3 and a rotatable quill or sleeve {1 on which the armature is mounted and to whichit is secured. The quill or sleeve 42 surrounds a driving axle 5 of an electric locomotive, or other vehicle having driving wheels 6 (only one of which is shown) secured to its respective ends in the usual manner. The sleeve or quill 1 is provided with a plurality of projections 7 extending radially outwardly to which arms 8- are secured by bolts 9a The arms 8 extend between the spokes 10 ofthe wheels 6, and driving springs 11 are tangentially interposed between the wheel spokes and the arms, their center lines being perpendicular to centrally disposed radial planes.

While anumber of springs will, of course,

bev employed; for each wheel to constitute a complete driving connection, each; pair of them issimilarly supported and symmetrically arranged so that I deem it unnecessary to describe-pr illustratemore than one pair.

Referring especially to Fig. 1, the spring 11 comprises a plurality of closed end turns separated .by a number of open turns of varying diameters, as hereinafter more fully pointed out. .One end of the spring is secured to the arm 8 by means of a ring 12, which is integral with the arm 8 and is screw-threaded, internally, to receive the convolutions of the spring. A cylindrical plug 13, the outer surface of which is screwthreaded to engage the convolutions of the spring, is expanded into the end of the spring, inside the ring 12, by means of a wedge 13 and rigidly clamps the spring in position. The opposite end of the spring is similarly secured to the wheel spoke 10, except that a ring 14, which is removably secured to the wheel structureby bolts 15, is substituted for the ring 12.

The details of the plug 13 are clearly shown in Figs. 3 and 4 of the drawings.

When an ordinary helical spring is em ployed in a driving connection suitable for the above-indicated purposes, it is found desirable to make the spring somewhat longer than is necessary to give the best results, as far as the compression and tension strains are concerned, in order to relieve the spring from excessive strains when forces are applied which tendto laterally displace it. By utilizing the spring of my present invention, the strains which are imposed upon it by reason of forces tending to displace it laterally, are not materially changed, while the capacity of the spring to sustain forces in compression and tension is very much increased. Those skilled in the art will readily understand that, in starting and suddenly accelerating a locomotive, the loads temporarily thrown upon the driving connections are very greatly in excess of the normal running loads, and, consequently, the advantages of my improved spring in such connections ,are apparent.

In order to illustrate more fully the characteristics of my spring, reference may be had to Fig. 2, in which the line a is the locus of points obtained by determining the de flection of an ordinary helical spring under varying loads. Curve b indicates the corresponding locus for a spring constructed in accordance with my present invention. By comparison of these two curves, it,is evident that practically the same deflection occurs in each case for the lower loads, but, as indicated by the upper part of the curve I), my improved spring is capable pf withstanding very much larger 'loads' for increased deflections; On the other hand, the reduced diameter of the middle turns of the spring does not materially affect the amount of deflection produced by a given side stress,

so it is evident that I have retained-higher resiliency, While I have, at the-same time, increased the capacity of thespring.

By closing the end turns of the spring where it is rigidly gripped by the clamping members, I avoid any tendency to produce irregular bends in the spring when extremely heavy loads are applied. If openturn springs are employed and the end turns rigidly gripped, there will, of course, be a tendency to produce irregular bends close to the clamps when a sufiiciently heavy load is applied to the spring to close the intermediate turns.

I claim as my invention:

1. A resilient connection comprising '-,a helical spring having closed end turns of substantially equal diameters and intermediate turns of varying diameters, and spring grips comprising nuts into which the end turns of the spring are adapted to be screwed, and wedge blocks adapted to grip the end turns internally.

2. A helical spring composed-hi substan-.

tially closed end turns of equal diameter and open intermediate turns of varying diameters, the turns of the smallest diam eter being in the middle of the spring.

3. A resilient connection comprising a helical spring having closed end turns of substantially equal diameters and intermediate turns of varying diameters and means for rigidly gripping the closed turns.

4. The combination with two relatively movable members, of an interposed helical spring, the end turns of which are closed, and means for circumferentially gripping the closed convolutionsof said spring and 1c)lamping the same to the respective memers. Y

5. The combination with two relatively movable members, of an interposed helical spring, the end turns of which are closed and the intermediate turns of which are of varying diameters, and means for circumferentially gripping the closed convolutions of said spring and clamping the same to the respective members.

6.'.The combination. with an electric motor having arms projecting radially from its rotatable member, of a wheel having spokes which alternate in position with, said radial arms, helical springs interposed between said arms .and said spokes and. having closed end. convolutions and. clamps which circumferentially grip said..,closed convoluti'ons. ofthe'springs both internally and externally and rigidly fasten-the same to said arms and spokes. Y

7. The combinationiwith an electric motor having arms projecting radially from its rotatable member, of a wheel having spokes which alternate in position with said radial arms, helical springs interposed between said arms andsaid spokes having closed end convolutions and intermediate convolutions of varying diameters, and clamps which circumferentially grip said closed convolutions of the spring, both internally and externally, and rigidly fasten the same to said arms and spokes.

In testimony whereof, I have hereunto subscribed my name this 21st day of July,

JOHN E. WEBSTER. Witnesses:

E. E. WHITNEY, B. B. HINEs.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents.

Washington, D. C." 

